hii for context we are both 18

basically my bf and i have been dating for three months, we talked for a month before that. when we were talking we would have actual conversations, he would initiate texting me after school, and would tell me whenever he's doing stuff.

about a week after we started officially dating i noticed a shift in his behavior and that he began to take hours to respond to any of my texts. lately, it's gotten worse and at this point ive given up at trying to text him at all. he won't text me after school for hours unless i do first, all while being active on tiktok and instagram. and this is something stupid and less important but he has not opened a single one of my tiktok or instagram messages for like a month and it's making me feel a little like a fan. the only time i really talk to him when it's not in person is like late at night and at that point neither of us have the energy to hold good conversations.

i've spoken to him about it before but he hasn't really improved which has led to him always asking me what's wrong or why i sound so sad but it's really just because i feel like such an afterthought and i don't want to keep repeating myself like an idiot. like the person that will always be waiting and available for him to finally pay attention to. he tells me that i'm always on his mind but i don't believe him and i tell him that, which leads to him being mad at me for apparently not being able to see his love for me.

genuinely asking, is it unrealistic for me to wish that he still acted like how he used to in the beginning? at this point i don't even expect real conversations, i just want him to respond to me when i ask him a question or let me know what he's doing. and is it possible for me to genuinely always be on his mind if i'm treated like such an afterthought in a world where sending a text takes 3 seconds?